Lesson 5 - Hair Analysis Friday 20 May 2011:


Learning Intention: We are learning to

1. think about the process involved in developing a technique for forensic analysis

2. identify the physical structures of hair

3. use our observational skills, critical thinking and microscopy


Background information
Unfortunately hair is not the best type of physical evidence for establishing identity. It is not possible to show with any certainty that two hairs came from the same person or animal. However hair can be used to rule out certain suspects or scenarios. It can also be used to corroborate (support) other physical evidence if it is consistent with the rest of the evidence.

Guide to Identification

Cuticle - Outer coating composed of overlapping scales
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Medulla - Central core, this may be absent
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Cortex - Protein rich structure surrounding the medulla; contains pigment
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Fill in the Identification Chart


Cuticle
Cortex
Medulla
Other Characteristics
Human A
Flat, smooth
Browny and medium thickness
Continuous
smooth narrow, darker at end
Human B
Flat, smooth
thin brown
Continuous
black at end
Human C
Flat, smooth
light brown
Continuous
blobby at tip.
Horse




Dog




Cat
Flat, smooth
Fat
Thick
bolby
Rabbit
Flat, smooth
Black, Thick
Present
ridged thin at tip.



A Crime Scene is a scene where a crime has been committed for example, a murder or a robbery. There are many steps that you have to go through when a crime has been committed. Some things that you do is to investigate the crime scene, find and collect evidence, take to a lab to be examined and then eliminate suspects to find the offender. The last step will be to catch the criminal and then take them to court.

The first people to arrive at a crime scene are the scene of the crime officers (soc). The (soc) first have a look around the crime of the scene but the have their hands in their pockets to make sure that they don’t disturb anything. After they look at the crime scene they will search around the area and find any evidence such as fingerprints, blood, hair and clothing. The (soc) brush the fingerprints with a fine dust and then lift the fingerprints with a gel pad and then they will store it in a bag ready to be taken to a lab.

When all of the evidence has been collected and delivered to the lab, scientists examine the evidence to find who the evidence belongs to. It can take up to four days to find possible people who fingerprints belong to. The fingerprints that they will find will either by 1 of 3 possible fingerprints. One of the possible fingerprints will be an arch another is a Whorl and then the last one is a loop. When the scientists have figured out possible suspects for the evidence they will then report it and then Police Investigators will drive to the suspects house to ask them some questions.

When the Police Investigators arrive at a suspects house they will ask them questions like “Where were you at 7:30pm last night”. “Do you have anyone who can prove that”. The investigators will either ask questions at your home or take you to an interview room so they can record what you say in the interview. Police Investigators will then re visit the crime scene to find what happened there so they can get an idea of what kind of person they are dealing with. After they have interviewed suspects and re visited the crime scene for more clues, detectives will put all of the suspects word’s together and then eliminate suspects to find the offender or culprit.

After the culprit or offender is found they will take them to court, and ask him why he or she committed the crime and then decide wether the person is guilty or not guilty. After the decision is made the offender will be sentenced for the crime they have committed.




































Cuticle
Cortex
Medulla
Other Characteristics
Human A
Flat, smooth
Browny and medium thickness
Continuous
smooth narrow, darker at end
Human B
Flat, smooth
thin brown
Continuous
black at end
Human C
Flat, smooth
light brown
Continuous
blobby at tip.
Horse




Dog




Cat
Flat, smooth
Fat
Thick
bolby
Rabbit
Flat, smooth
Black, Thick
Present
ridged thin at tip.